Grinder for dressing skins



Oct. 2, 1934. M CURTI 1,975,349

GRINDER FOR DRESSING SKINS Filed April 23, 1934 f. INVENTOR.

GEORGE M. CUPT/IY.

oi W

ATTORNEY.

Patented Get. 2, 1934 I UNITED STATES PATENT OFFICE I 1,975,329 GRINDERFOR DRESSING SKINS George M. Curtin, Gloversville, N. Y. ApplicationApril 23, 1934, Serial No. 721,902 6 Claims. (Cl. 149-14) This inventionbroadly relates to improvements in abrading machinery especially of thewide faced drum type adapted to dress fine tanned leather goods forglove making and the like purposes, and is more particularly concernedwith certain protective devices that prevent the treated skins fromunduly hugging or being inadvertently wrapped around an abrasive drumsurface when operatively fed thereto.

The present instrumentalities are applicable to a dry skin grinder ofthe type disclosed in the Feix Patent No. 1,241,363 dated September 25,

I 1917. Such a machine may comprise a rapidly revolving abrasive drumtogether with a feed or so-called presser roller that is reverselydriven but at a relatively slower speed and made bodily shiftable towardor away from its cooperating abrasive drum. A marginal portion of a skinwhile longitudinally stretched in an unwrinkled condition, is dextrouslymanipulated and gradually fed to this machine with its flesh sidepressed snugly toward the abrading drum to remove its superfluousmaterial. This operation results in a tanned leather product that ismade uniformly thin. After reaching the medial surface region, thetreated skin is generally withdrawn by selectively releasing the presserroller and the skin then reversed from end to end to similarly processits remaining unfinished flesh surface. During such procedure it is notan infrequent occurrence that the skin adheres unduly to the abrasiveroller and is carried around therewith with a resulting abnormal wastageof material. Whenever the skin tends to grip in such fashion, theoperator manually reaches underneath the fast rotating abrasive drum tofree the skin during its incipient seizing period, but such practice isattended with considerable hazard and has in the past, frequently ledto'serious maiming of many experienced machine attendants.

The preventive measures herein embodied are centered in jet means whichpreferably eject a blast of air or other gaseous fiuid tangentiallyagainst the abrasive drum in a direction counterwise to the path of theincoming treated product. The nozzle for my continuous air stream is sodisposed that .it will efficiently pick off and surmount the drumhugging tendency displayed by machine treated skins, it having beenfound that such unremittent safeguard effectively obviates thefabrication difliculties usually encountered when skin seizure occurs.

The abrasive drums are commonlybuilt up from heavy cardboard discs orthe like compressed fibrous material and the cylindrical surface ofwhich has granules of abrasive glued thereto. After becoming dull orworn, such superimposed cutting surface is renewed in place, and

in order to avoid clogging and otherwise defiling my safetyappurtenances, the entire blower equipment is preferably installed as ademountable machine accessory.

The-object of my invention is to provide for a trustworthy yet extremelysimple device of the character indicated and one that can readily beapplied to either existing or new grinders without requiring extensivechanges in the structure thereof. .Other objectives will appear in duecourse and all of which aspects will hereinafter be set forth in detail.

Reference is had to the accompanying one sheet of drawings which isillustrative of a specific embodiment of my invention and in which draw-Fig. 1 schem tically represents an elevational cross-section of agrinder machine as taken transversely of the medial region of itsabrasive roller and equipt with my improved devices; while Fig. 2 showsa horizontal'view thereof as seen from line 2-2 of Fig. 1.

Referring first to the more conventional elements of a dry skin grinderassembly of the kind comprised in the cited Feix patent, these prima-'rily include a belt driven abrasive drum 10 which relatively massivepart may be mounted between a pair of shaft journals such as 11 androtated at a relatively high speed by the pulley 12. Said journals mayrespectively be carried upon complementary horizontal girders such as 13that are spacedly supported by the upright framework 14. The lowermostportion of the framework may be equipt with a pair of crossbars such as15 which respectively lie beneath said complementary girders. Thesecrossbars may respectively be provided with an auxiliary journal such as16, having a cross-shaft 17 mounted therebetween.

Each upturned girder face may be fitted with a separate guideway 18;respectively resting thereon is a shiftable carriage element 19 andacross which is suspended a work table 36 for holding treated skins.Rack and pinion means such as 20 may serve to' simultaneously actuatethe respective carriage elements toward or radially away from the drumaxis. To this end, a pinion rockshaft may be extended laterally to havea toggle arm 21 attached thereto, said arm being linked to the pivotedfoot treadle 22. If desired, an adjustable counterweight 24 or itsequivalent may be used to load and thereby automatically thrust thecarriage elements 19 inwardly toward the abrasive drum surface inreleased treadle position. Mounted between said carriage elements is asheathed presser or feed roller 25 which may be brought closelycontiguous to the abrasive drum surface but which roller may bewithdrawn whenever the treadle is depressed. Said roller lightly pressesthe interposed skin against the abrading drum surface.

It is preferred to positively and continuously rotate the shiftable feedroller from the pulley 12 in a reverse direction from that of the drum.In the present instance, the drive is accomplished by the conventionalchain and sprocket reduction gear 26 represented in Fig. 1. As indicatedin dotted outline, supplementary guide rollers 27 and 28 may beinstalled to cooperate with the feed roller, but all such subordinatemembers merely assist in properly guiding the treated skin 29 betweenthe drum l0 and the feed roller 25.

Referring now more specifically to the improvements applied to thedescribed conventional grinder members, these may comprise a blast meansof any suitable type or design but preferably such that includes acasing 30 and a rotatable fan or blower 31 which may be independentlydriven in unison with the drum 10- by a direct connected motor 32. As analternative, saidblower may also be driven from the pulley 12 or theblast taken from any other convenient source, the intent being to insurean adequate blast supply during the period of grinder operation.

The blower casing 30 is shown provided with a flange 33 which may bedetachably secured to a contiguous portion of the framework 14. Saidcasing may further be equipt with a contracted delivery spout 34,preferably of the multiple nozzle type adapted to distribute the airblast lengthwise of the drum through a series of laterally disposed jets35A, 353, etc.

Each such nozzle may be arranged underneath the rotating drum closelycontiguous to but distant from the abrading surface so as to ejectupwardly toward the rotating drum in tangentially counterwise or otheropposed relation to the surface movement, as shown. The use of aplurality of such jets is however, not essential since a single nozzleblowing medially of the drum will normally suffice to start the leadingextremity of a relatively small skin away from the abrasive surface,which in turn effectively extricates and overcomes the inherent tendencypossessed by such treated skins to carry wholly aroundwith the rotatingdrum.

It is thought the function of my tangentially directed air stream willnow be apparent to those skilled in this art. When the treated skin isdescendingly fed through the described machine, its leading extremityusually drops away from the drum, but should its initial surface grippersist in dragging said skin into the operative region of my airblast,. such jet or jets serve in the capacity of a sentinel to promptlypick up and cause the loosened leading skin end to pull away from thedrum, whereupon its overhanging weight assists in drawing the remainingtrailing skin portion free from the abrading surface. Should it, afterrepeated dressing of the drum surface, become necessasry to renew theglued abrasive material, it is preferred to bodily remove the blastnozzle out of the way in order not to clog or otherwise befoul the samewith drippings.

As a further outstanding feature, all working parts required to loosenthe treated. skin, are

herein deliberately kept spaced from the drum profile; that is to say,by the use of an air blast as projected to play upon the distant drum,none of the accessory elements need actually contact with its cuttingsurface nor be subjected to rapid abrasive action. In addition, my fluidspray when given sufficient penetration, tends to cleanse the abrasivedrum surface from any abnormal accumulation of adhering foreign matterwhich might otherwise be deposited thereon because of skin treatment.

It is to be understood that various other structural modifications maybe resorted to in likewise carrying out my illustrative embodiments, allwithout departing from the spirit and scope of my invention heretoforedescribed and more particularly pointed out in the appended claims.

I claim:

1. In a machine for treating skins or the like, the combination ofrotatably mounted drum means provided with an abrasive surface, feedroller means cooperating with said drum, drive means for rotating thedrum surface, and blast means ejecting a gaseous fluid toward the drumin an opposed direction to the drum surface movement.

2. A skin processing machine comprising r0- tatably mounted drum meanshaving a cylindrical abrasive surface, feed roller means cooperatingwith said drum, drive means for rotating the drum surface, and air blastmeans including a nozzle that is kept spaced from said drum surface anddirects a jet of air thereagainst for skin piekoif purposes.

3. A skin processing machine comprising rotatably mounted drum meanshaving a cylindrical abrasive surface, feed roller means cooperatingwith said drum, drive means for rotatlng the drum surface, and blastmeans including a plurality of nozzles that are distributed lengthwisealong said abrasive surface and respect-ively disposed to ejectthereagainst.

4. A skin dressing machine comprising mounted drum means having anabrasive surface, cooperating feed roller means that are selectivelymovable toward or away from said drum, drive means for positivelyrotating the drum and the roller at different speeds, blast meansincluding a rotatable blower element togetherwith a nozzle ejectingtoward the abrasive drum surface, and means for rotating said blower inunison with the drum. 5. In a skin treating machine, the combination ofdrum means having an abrasive surfaceand which drum is rotatablysupported by an underlying framework, feed roller means cooperating withsaid drum, drive means for rotating the drum, and blast means includinga jet nozzle that is detachably upheld beneath said drum by saidframework and which nozzle is directed to eject upwardly against theabrasive drum surface.

6. In a machine for treating skins or the like, the combination ofrotatably mounted drum means provided with a cylindrical abrasivesurface, presser roller means cooperating with said drum in contiguousperimetric relation to receive a skin therebetween, drive means forrotating the drum, and means ejecting a fluid stream toward the abrasivesurface and which stream loosens a leading skin portion from saidsurface after having passed through the aforesaid perimetric reion.

GEORGE M. CURTIN.

